Pump



Feb. 28, 1967 H. P. TYLER EUMP Filed March 26, 1964 United States PatentGitice 3,385,289 Patented Fei). 28, 1957 3,305,299 FUMP Henry P. Tyler,South Bend, Ind., assigner to The Bendix Corporation, South Bend, Ind.,a corporation of Delaware Y Filed Mar. 26, 1964. Ser. No. 354,887 2Claims. (Cl. 1tl3-6) This invention relates to a pump capable of usingmechanical power to pressurize and proportion multiple liquids suppliedto it.

lt is a principal object of my invention to provide a pump havingmultiple stages or sections each of which is capable of independentlypumping a uid and/ or propoztioning a combustion of fluids while pumpingthem.

lt is a further object of my invention to provide a pump asaforementioned with a pressure responsive control means common to allstages.

It is also an object of my invention to provide a pump with a means tocirculate the incoming iluid throughout the pump to provide coolingbefore pressurizing.

Still another object of my invention is to provide an electrohydraulicservo valve for controlling the above mentioned pressure responsivecontrol means.

A still further object of my invention is to provide a multiple stagepump which is so constructed to allow access to any stage thereofwithout complete disassembly.

An additional object of my invention is to provide a pump having meansto proportionally mix two fluids and thereafter deliver same.

A further advantage of my invention is in the means for allowing thepassage of liquids through each of the pump stages in the directionsnormally induced, even though that stage is non-operating.

Other objects and advantages will be apparent from the followingdetailed description of the invention as related to the drawing showinga cross-sectional form of a three stage pump and control meansconstructed in accordance with the principles of my invention.

As seen in the drawing I have provided a pump 1t) f having threedistinct rotors 12, 14 and 16, on a common axis each of which is aixedto respective. shaft portions 18, 2li and 22 that are interconnected byappropriately designed spline lits so as to provide a common drive meansconnected to a stub shaft 24 that may be driven by a power plant (notshown). Each of the rotors contain reciprocating plungers; i.e., rotor12 has reciprocating plungers 26, rotor 14 has reciprocating plungers 28and 30, and rotor 16 has reciprocating plungers 32.

As will appear obvious to those skilled in the art, the purpose of theseplungers is to draw in uid from each of the fluid inlets 34, 36, 38 and40 and expel fluid at discharge ports 42, 44 and 46. It should be notedthat the discharge at port 44 will contain a combination of fluidsingested at inlets 36 and 40, as will be hereinafter further explained.

The plungers are reciprocated by a non-rotating, tiltable cam plate (S)48, S and 52 each of which are mounted by trunnion bearings in thehousing (not shown) as are familiar to those skilled in the art to whichmy invention relates. Smooth, sinusoidal motion is imparted to theplungers by means of shoes 54 or 56 and 58 having respective swivelsockets 60, 62 and 64 connecting the respective plungers thereto.Additionally, the plungers 36 are similarly mounted to shoes 66 byswivel sockets 68.

Plunger retraction does not depend upon individual cycling springs,which could be provided if desired, but rather is semi-positive.Auxiliary cam plates 70, 72 and 74 provide the retraction by holding theplunger slippers or shoes 54, 56, 58 and 66 against the non-rotating,tiltable cam plates or swash plates, as they may be termed, as bysprings 76, 78 and 80 operatively connected to the auxiliary cam plates.lt should be noted that, as shown, centrifugal force supplementsretraction and axial play is limited by a shimmed physical stop orbearing plates 82V, 84 and 86. The result is reliable operation withhigh volumetric eiiiciency. Y

Each of the aforementioned rotors and reciprocating plungers iscontrolled by removable ported valve plates 88, 98 and 92, which bytheir removable nature allow for valving refinements and changes byrelatively flexible, quick, and inexpensive changes as compared to otherpump concepts familiar to those skilled in the art to which my inventionrelates. Pressure balanced ferrules 94, 96 and 98, for example, serve toseal the valve plates to the housing so that extreme running parallelismof rotor faces to housing faces is not required.

As seen in the drawing from the drive shaft 24 forward, the respectivesections are adaptable for pressurizing and providing multiple uids.There are no direct leakage paths between the sections containing rotors12 and 14 in order to allow the pumping of two or more fluids which mayreact violently if exposed to each other. Furthermore, the main housings180, 102, 104 and 166V part along the faces 108, 118 and 112 of each ofthe sections for individual access to the rotors 12, 14 and 16.

lt should be noted that the fluid introduced to plungers 30 by means ofinternal passage 114 is exhausted to another internal passage 116 thatis communicated with the internal inlet passage 118 for the plungers 28.Thus allowing the comingling of fluids to be exhausted by plungers 28lto the internal passage 120 terminating in the discharge port 44.

In order to provide for means of collection of fluid leakage, l haveshown the rotors 12 and 14 to have axial passages 122 and 124 whichcommunicate with radial passages 126 and 128 respectively in the valveplates 88 and 90 leading to an inlet for the plungers 26 and 28respectively. The inlet for the plungers 26 being provided by aninternal passage 130 and the discharge passage for the same plungersbeing provided by another internal passage 132. As for the rotor 16, Ihave provided a unique way rotating mechanism by allowing the uid fromthe inlet port 38 passing by way of passage 134 to be introduced toaxial passages 136 through the rotor to flow into a pump cavity 138 forthe rotor 16 and circulate around the aforementioned members beforebeing directed to another passage 140 formed by clearance between thehousing 106y and the rotor 16 that is arranged to communicate with aradial groove 142 in the valve plate 92 that opens into a bore 144 inwhich the plungers 32 reciprocate. This feature is very important ifreactive fluids are being pumped by the rotor 16 in that it willminimize the reactive nature thereof while, by passage of the large owrates (instead of only leakage rates) through the case, lowering thebulk temperature and reactivity rate. Furthermore, the centrifugalforces of the rotor 16 will force a correct coolant ow throughout thecavity 138.

The cam plates 48, 50 and 52 are positioned by means of a pair ofpistons 146 and 148 that directly position the swash plate 48 which islinked by push rods 150, 152 and 154 to the remaining cam or swashplates 50 and 52 as well as a spring return means 156. As seen, the pushrods contain simple O-ring type seals to allow fluid integrity of eachofthe pump cavities 158, and 138. The small pressure differentials inthe aforementioned cavities allow use of these relatively simple seals.In addition, similar seals will be appropriately provided in the housingsections to prevent fluid leakage from one cavity to the other about theshafts. l

Variable delivery control for each of the pump sections is provided bythe action of the two opposed actuator pistons 146 and 148 which withthe assistance of the push of cooling the rotating and nonrods 150, 152and 154 plus the return spring 156 govern the `angle of the cam pla-tes48, and 52 to cause the cam plates to move in unity. As seen the piston148 is biased by a spring 254 to maintain the abutting relationship ofthe pistons 146 and 148 with the swash plate 48. The pistons 146 and 148are positioned normally by duid pressure delivered thereto by internalpassages 161 and 162 that extend through housing sections 100 and 102 toemerge at respective orifice inlets 164 and 166 adjacent a machined faceof a radial ange for section 102 to which I have joined a dry coilmechanical feedback servo valve 168, as by vbolts (not shown), whichvalve is of a type -to have low hysteresis, with means to convert acommand signal to the required displacement of pumping elements, of asomewhat similar type as the Patent No. 2,964,018 issued December 13,1960, to the common assignee. More particularly, the permanent magnettype torque motor as will be embodied to bring about valve control andas is shown in the aforementioned Patent No. 2,964,018, is isolated fromthe hydraulic portions of the valve by a torque tu'be 170 which acts asboth a fluid seal and torque motor centering spring. Motor-developedtorque is transmitted through this tube to a flapper 172 which ispositioned to have portions thereof overlying but spaced from twoparallel nozzles 174 and 176 to increase, decrease or equalize the flowtherefrom. As seen, the nozzles 174 and 176 lare respectively connectedto passages 178 and 180 by the radial passages 182 and 184, and thepassages 178 and 180 terminate in respective valve chambers 186 and 188at each end of a spool valve 190.

Fluid pressures developed by a familiar :means such as a reservoir 192,a pump 194 and accumulator 196 having appropriate conduits 198 and 200connected respectively to an inlet 202 and an outlet 204 that is in turncommunicated with passages 206 and 208, respectively, extending throughsections 104 and 102 to enter the valve 168 by means of respectivepassages 210 and 212. The valve passage 210 terminates in an inletchamber 214 having a filter means therein which is arranged to filterthe pressurized fluid before its passage through the end locatedorifices 216 and 218 that communicate with the respective passages 178and 180. In addition, the inlet chamber 214 is `communicated by passages220 and 222 to respective grooves 224 and 226 in the valve housing 168that are normally closed off from communicating with an internal bore228 by the valve end lands 230 and 232. The spool valve 190 alsocontains center valve lands 234 and 236 which apportion the bore 228into three chambers 238, 240 and 242 which are respectively connectedwith passages 244, 212 and 246. As is also seen the apper 172 isprovided with a projection 248 which is adapted to ride between thelands 234 and 236 and thereby provide mechanical follow-up of valvemovement. Therefore, motion of the flapper 172 creates, a differentialpressure in chambers 186 and 188, which pressure acts on the ends of thespool valve `to displace it, so that either passage 220 or 222 iscommunicated by way of chambers 238 or 242 to passage 212 leading by wayof passage 208 to conduit 200 terminating at the reservoir 192. Due tothe mechanical connection of the fiapper to the v-alve spool 190,movement of the spool generates a countertorque through the feedbacktension spring to return the apper to the null position when the spoolhas reached the commanded position. Because of the inherent fastresponse of such a valve, action is modified by interposing the orifices164 and 166 in the passages connecting the servo valve stage chambers238 and 242 to the pump actuator pistons 148 and 146, respectively, andthereby slow pump response to the specified valve. i

In order to allow the passage of liquids through each of the stages ofmy pump in the directions normally induced, while non-operating, I haveprovided three ball check valves 253, 250 and 252 which parallel thenormal pumping paths as shown.

It should be noted that push rod links govern relative displacement ofthe pumping sections. And that by length revision the delivery ratesmaybe changed for each stage.

In operation, the pressurized hydraulic fluid delivered by conduit 198to inlet 202 and by appropriate passages to the inlet cavity 214 of theelectro-hydraulic valve 168 will normally ybe equally exhausted throughthe nozzles 174 and 176 to hold the valve spool 190 in the nullcondition and returned to the cavity or groove 240 which is communicatedby appropriate passages to the discharge 204 and the conduit 200 to thereservoir 192. In the event a control signal is provided to the torquemotor controlling the dapper 172 one or the other of the nozzles will berestricted to position one or the other of pistons 146 and 148 andthereby adjust the angle of the cam plates 48, 50 and 52 and vary thefluid discharge at ports 42, 44 and 45. It should also be understoodthat by varying the cam plate 50 and due to the concentric arrangementof plungers 2S and 30 the ratio of fluid discharged from plunger 30 tothe inlet for plunger 28 will remain constant.

Although this -invention has 'been described and shown with reference toa particular embodiment of the invention, the principles involved aresusceptible of numerous other applications and embodiments which will beapparent to persons skilled in the art. The invention is, therefore, tobe limited only as indicated by the scope of the appended claims.

I claim:

1. A multi-uid pump comprising:

a first, second and third pump having respective first,

second and third rotors, pistons and cam plates;

a means to collectively control each cam plate includlng! a pressureresponsive member arranged to operate one of said cam plates,

a link means to connect said one of said cam plates to each of the otherof said cam plates, and

a spring means operatively connected to said cam plates and link meansto oppose said pressure responsive member;

a control valve arranged to actuate said pressure responsive member;

a first passage means in said pump for delivering separate fluids toeach of said pumps with one of said passages adapted to supply a fluidto cool the pump before being circulated by centrifugal force to thepump pistons, and

a second passage means in said pump for exhausting fluids from each ofsaid pump means with one of said passages adapted to intermix a pair ofuids in a constant ratio throughout a control range for said pump; and

a bypass means for each of said fluids operatively connected betweensaid first and second passage means to permit normal circulation offluid regardless of pump operation.

2. A pump comprising:

a means to pump a plurality of uids including a means to ingest andpressurize each fluid;

a control means to modulate the amount of ingestion and pressurizationof each fluid;

a pressure responsive means arranged -to actuate said control meanshaving an interconnecting means for each of said control means;

a reference means operative-ly connected to said interconnecting meansand arranged to oppose said pres` sure responsive means;

a means to circulate each of said fluids through said pump regardless ofoperation of said means to pump the plurality of fluids;

a servo valve for said pressure responsive means, said servo valvehaving a housing;

a spool valve mounted reciprocally in said housing;

end chambers being defined between the spool ends and said housing, saidspool having a mid-position References Cited by the Examiner UNITEDSTATES PATENTS 1,322,236 10/1919 Fish 103-9 2,445,281 7/1948 Rystrom103-162 DONLEY J.

6 McGowan 103-6 Chiantelassa 103-11 Blenke 103-162 Budzich 10? 162Manning et al. 103-162 Pesce 103-162 Boydell 103-4 Laing 103-5 Tyler103-162 Korlak 103-9 STOCKING, Primary Examiner. MARK NEWMAN, Examiner.

W. L. FREEH, Assistant Examiner.

1. A MULTI-FLUID PUMP COMPRISING: A FIRST, SECOND AND THIRD PUMP HAVINGRESPECTIVE FIRST, SECOND AND THIRD ROTORS, PISTONS AND CAM PLATES; AMEANS TO COLLECTIVELY CONTROL EACH CAM PLATE INCLUDING, A PRESSURERESPONSIVE MEMBER ARRANGED TO OPERATE ONE OF SAID CAM PLATES, A LINKMEANS TO CONNECT SAID ONE OF SAID CAM PLATES TO EACH OF THE OTHER OFSAID CAM PLATES, AND A SPRING MEANS OPERATIVELY CONNECTED TO SAID CAMPLATES AND LINK MEANS TO OPPOSE SAID PRESSURE RESPONSIVE MEMBER; ACONTROL VALVE ARRANGED TO ACTUATE SAID PRESSURE RESPONSIVE MEMBER; AFIRST PASSAGE MEANS IN SAID PUMP FOR DELIVERING SEPARATE FLUIDS TO EACHOF SAID PUMPS WITH ONE OF SAID PASSAGES ADAPTED TO SUPPLY A FLUID TOCOOL THE PUMP BEFORE BEING CIRCULATED BY CENTRIFUGAL FORCE TO THE PUMPPISTONS, AND A SECOND PASSAGE MEANS IN SAID PUMP FOR EXHAUSTING FLUIDSFROM EACH OF SAID PUMP MEANS WITH ONE OF SAID PASSAGES ADAPTED TOINTERMIX A PAIR OF FLUIDS IN A CONSTANT RATIO THROUGHOUT A CONTROL RANGEFOR SAID PUMP; AND A BYPASS MEANS FOR EACH OF SAID FLUIDS OPERATIVELYCONNECTED BETWEEN SAID FIRST AND SECOND PASSAGE MEANS TO PERMIT NORMALCIRCULATION OF FLUID REGARDLESS OF PUMP OPERATION.